Re: questions about disk configurations

From: eric soroos <eric-psql(at)soroos(dot)net>
To: pgsql-performance(at)postgresql(dot)org
Subject: Re: questions about disk configurations
Date: 2002-12-09 21:42:02
Message-ID: 88699896.1172681174@[4.42.179.151]
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>
> Er, no, it's not. In fact, for a 3-disk config, I reccommend:
>
> Disk 1: OS, swap, system logs
> Disk 2: Data + Indexes
> Disk 3: Transaction Log

What is the accepted way of splitting the data from pg_xlog?

I've been testing some configurations for low budget performance, and I haven't been able to make this help vs. one disk. (under osx, ymmv)

I rsync'd the pg_xlog directory to another disk, then set up a symlink pointing from the data/pg_xlog to /other/disk/pg_xlog.

I then got tps numbers that were 2/3 of the single ide drive speed. The only explanation I can come up with is that something is seeking to the symlink, then doing the actual write on the other drive.

I'm going to try this under linux using mount points, but I need to shuffle hardware first.

any ideas?

eric

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